cmake DEAL_II_HAVE_FP_EXCEPTIONS examples

dealii/dealii cmake/checks/check_01_cxx_features.cmake :463 

CHECK_CXX_SOURCE_RUNS("${_snippet}" DEAL_II_HAVE_FP_EXCEPTIONS)

dealii/dealii cmake/checks/check_01_cxx_features.cmake :469 

CHECK_CXX_SOURCE_COMPILES("${_snippet}" DEAL_II_HAVE_FP_EXCEPTIONS)